It is straightforward to plug a fluorescent tube into a mechanism for installation of a lamp of the prior art, but since a typical mechanism of the prior art uses a spring plate to hook a bolt with a stopper therein. Using a tool to unplug a fluorescent tube is necessary, but it is inconvenient to a user. It is a further disadvantage that mechanisms of the prior art are complex and thus have more parts, which causes higher production cost and higher malfunction rate.